The abstract is more informative than the press coverage: http://onlinelibrary.wiley.com/doi/10.1002/aenm.201700345/abstract http://onlinelibrary.wiley.com/doi

The abstract is more informative than the press coverage: http://onlinelibrary.wiley.com/doi/10.1002/aenm.201700345/abstract http://onlinelibrary.wiley.com/doi/10.1002/aenm.201700345/ab... The cell is assembled in a mini-module with a geometric concentration ratio of 744 suns on a two-axis tracking system and demonstrated a combined module efficiency of 41.2%, measured outdoors in Durham, NC. Taking into account the measured transmission of the optics gives an implied cell efficiency of 44.5%. Since this is a concentrating cell, compare to the concentrator cell records tracked on NREL's PV efficiency records chart: https://www.nrel.gov/pv/assets/images/efficiency-chart.png https://www.nrel.gov/pv/assets/images/efficiency-chart.png The current record for 4-junction-or-more concentrator cells is 46.0%. This isn't a record-setting cell even if the implied efficiency holds up under standardized test conditions. This cell like all high-concentration cells is unlikely to see mass market acceptance on Earth. The module needs precise two-axis sun tracking to work effectively even under perfect clear-sky conditions. That's significantly more expensive than fixed arrays or single-axis sun tracking as used by conventional large scale PV. And there's a vicious feedback loop: since two-axis tracking is significantly more expensive, it doesn't get developed/scaled, so the cost gap gets even wider over time WRT its competitors. But that's not actually the worst problem of high-concentration PV for terrestrial use. The worst problem is that HCPV can use only direct normal irradiance. Ordinary non-concentrating PV cells produce very nearly 25% of its rated output if it receives 25% of test-condition illumination under non-ideal conditions (due to some combination of clouds, air pollution haze, dusty glass, etc.) Concentrating cells will produce close to 0% of rated output under the same non-ideal conditions. Few regions have clear enough skies to work with HCPV, but those same regions tend to be dusty, which the concentrating optics cannot tolerate. Mechanical and optical complications make HCPV higher-maintenance than ordinary flat PV and more expensive to install initially. That's why there were a dozen+ companies working on concentrating PV in 2008 and all of them are now bankrupt or have exited HCPV manufacturing. Eking out another cell-level improvement wouldn't have rescued the value proposition of their complete systems. The refined polysilicon price spike that made exotic technologies look briefly promising only lasted a few years and then it became clear again that crystalline silicon is very hard to beat.